Because environmental issues are increasingly being taken into account, greenhouse effect, mainly caused by carbon dioxide, is especially in particular need of improvement. It will be very helpful to improve environmental problems by providing a material that can convert carbon dioxide-containing gas, such as exhaust gas or flue gas discharged from a factory, into an economically valuable substance.
Conventionally, for increasing contact opportunity of a catalyst and reactants, particle size of the catalyst is minimized to increase its surface area. The minimized catalyst can be applied to part of industrial processes (e.g. Catalytic Cracking Reaction System in the petroleum industry). But in general, a catalyst having too small of a particle size is inconvenient to use. Therefore, in the industrial process, the particle size of the catalyst is formed larger in the shape of balls or cylinders. It is also possible to fill the catalyst in a tube to form a fixed bed reactor. However, a considerable pressure drop will occur when fluid passes through the fixed bed reactor. This phenomenon is more significant when the catalyst has smaller particle size and the flow rate of the fluid increases. Therefore, it is necessary to increase the pressure to push the gaseous reactants to pass the catalyst bed, and thus the fixed bed reactor is not suitable for treating large amounts of exhaust gas.
Chen et al. discloses a hydrogenation catalyst in U.S. Pat. No. 9,433,932 having a nanonickel carrier, and noble metal nanoparticles selected from Pd, Pt, Ru, Rh, or a mixture thereof, which are mounted onto the nanonickel carrier. The hydrogenation catalyst is advantageous for catalyzing hydrogenation of an aqueous compound with a benzene ring. However, the hydrogenation catalyst disclosed by Chen is a one-dimensional nanonickel carrier (nano-wire), it is not good for the staking use of the nano-wire catalyst. In addition, the hydrogenation catalyst does not show an activity for reducing carbon dioxide, and an ability of converting carbon oxides into a low carbon hydrocarbons.
It is therefore necessary to provide a nano-nickel catalyst and a hydrogenation device for treating carbon dioxide efficiently, in order to solve the problems existing in the conventional technology as described above.